Goose, dairy products are handy! I use milkstone remover as my acid cleaner and beerstone remover in all cases, for draught lines, kegs, fermenter... It's way cheaper than the acid products like 5 Star BS Remover and other acid products available to homebrewers (or pros for that matter) and identical in composition. And as an acid rinse following alkaline cleaners, way cheaper than SaniClean or the like (but not cheaper than white vinegar I suppose.) I guess the simple fact is that dairy farmers simply can't and won't pay up like homebrewers are willing to, and you can repackage a product and sell it to someone for as much as they will pay. Next time I pick up a jug of milkstone remover I'll look at the bulk tank cleaner. (You can get these things at Tractor Supply, but you do need to go to a store in an area where there are a lot of dairy operations, not every suburban TS will have them. I go to your Wooster store, Goose.)